In article ,
Tim Wescott wrote:

On Mon, 18 Mar 2013 15:54:19 -0400, Bob Engelhardt wrote:

35 lb tungsten "ballast" blocks (race cars): $1877

http://www.stockcarsteel.com/tungsten/

Twice as dense as steel & 50% more than lead, but what a price to pay
for the little space that it saves.

I used to work at an aerospace company that made extensive use of
tungsten weights in an assembly that had to be balanced just so, and was
a 5.000 pound bag with 4.999 pounds of s**t in it.

Sometimes they could use brass.

When the assembly costs enough, a few chunks of tungsten aren't that much
by comparison.



They used to (and may still for all I know) use depleted uranium for
control surface balance weights on some large commercial & military
aircraft. IIRC, it's like 68+% heavier than lead. (Have also heard,
possibly here in this NG, that the military uses it for some projectiles
as well.)

I know that after a crash of an aircraft equipped with DU weights,
finding them is a big priority.

Erik